Benzodiazepine prescription and length of hospital stay at a Japanese university hospital

BACKGROUND: The relationship between bed days and benzodiazepine prescription (BDZ) in Western countries is inconclusive, and no hospital-based report has documented this phenomenon in Japan. This study was done to assess the association between bed days and BDZ in a Japanese hospital. METHODS: 21,489 adult patients (55.1% men, mean age 59.9 years old) hospitalized between April, 2005 and December, 2006 were enrolled in the study. Patient age, sex, ICD-10 diagnosis, prescription profile, and days of hospital stay were assessed in 13 non-psychiatric departments using a computer ordering system. Patients prescribed a benzodiazepine during hospitalization were defined as positive. RESULTS: Of the total sample, 19.9% were allocated to the benzodiazepine (+) group. Female sex and older age were significant factors associated with benzodiazepine prescription. The median number of bed days was 13, and the likelihood of BDZ significantly increased with the number of bed days, even after controlling for the effects of age, gender, and ICD-10 diagnosis. For example, when the analysis was limited to patients with 50 bed days or longer, the percentage of BDZ (32.7%) was equivalent to that of a report from France. CONCLUSION: Irrespective of department or disease, patients prescribed benzodiazepine during their hospital stay tended to have a higher number of bed days in the hospital. The difference in the prevalence of BDZ between this study and previous Western studies might be attributed to the relatively short length of hospital stay in this study. Because BDZs are often reported to be prescribed to hospitalized patients without appropriate documentation for the indications for use, it is important to monitor the rational for prescriptions of benzodiazepine carefully, for both clinical and economical reasons.